| Index: src/runtime/runtime-classes.cc
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| diff --git a/src/runtime/runtime-classes.cc b/src/runtime/runtime-classes.cc
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| index c13e55eebf3387e7f60a5309dc85d60265e578d2..2165652f031c783e2e5da3f4a9b07b2d2bf7fb3a 100644
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| --- a/src/runtime/runtime-classes.cc
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| +++ b/src/runtime/runtime-classes.cc
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| @@ -108,7 +108,7 @@ static MaybeHandle<Object> DefineClass(Isolate* isolate, Handle<Object> name,
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|                                       isolate->factory()->prototype_string(),
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|                                       SLOPPY),
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|            Object);
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| -      if (!prototype_parent->IsNull() && !prototype_parent->IsSpecObject()) {
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| +      if (!prototype_parent->IsNull() && !prototype_parent->IsJSReceiver()) {
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|          THROW_NEW_ERROR(
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|              isolate, NewTypeError(MessageTemplate::kPrototypeParentNotAnObject,
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|                                    prototype_parent),
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| 
 |